Articles

What constitutes proof? How much weight can we put on research results?

I’ve been reporting on memory research for 20 years, and this issue has always been at the back of my mind. Do my readers understand these questions? Do they have the background and training to give the proper amount of weight to these particular research findings? I put in hints and code words (“pilot study”; “this study confirms”; “adds to the evidence”; “conclusive”; and so on), but are these enough?

So here is the article I’ve always meant to write.

Short-term vs long-term memory

Working memory is a relatively recent term, a refinement of an older concept - that of short-term memory. Short-term memory was called thus to distinguish it from "long-term memory" - your memory store.

Research with children has demonstrated that the ability to learn new words is greatly affected by working memory span - specifically, by how much information they can hold in that part of working memory called "phonological short-term memory". The constraining effect of working memory capacity on the ability to learn new words appears to continue into adolescence.

Genes

Several genes have been implicated in Alzheimer's, but the big one is the e4 allele of the ApoE gene (on chromosome 19). This variant is found in about a quarter of the population.

Having it doesn't mean you are foreordained to develop Alzheimer's, but it certainly increases the risk substantially. The risk goes up considerably more if both of your genes are the e4 variant (remember you inherit two: one from each parent).

To celebrate Māori Language Week here in Aotearoa (New Zealand), here's some mnemonics to help you learn 25 common words in te reo. These use the keyword mnemonic. Keywords are written in italics.

aroha (love), an arrow in the heart

awa (river), a water flowing

hīkoi (walk), hike

hui (gathering, meeting), a lot of hooey is spoken at meetings!

iti (small), itty bitty

Have you ever been driving a car and suddenly you’re not sure what to do? You’re traveling along in usual automatic fashion and there comes a moment when you need to engage a new subroutine — say, you need to give way at an intersection, or you stall at the traffic lights, or you stop the car — and suddenly, you don’t know what to do. There’s a flash of panic, even while you’re thinking, “This is stupid, I’ve done this a thousand times”, and then, maybe it’s all right, maybe you have to take a moment to get your head in the right space, and ...

A Scientific American article talks about a finding that refines a widely-reported association between self-regulation and academic achievement. This association relates to the famous ‘marshmallow test’, in which young children were left alone with a marshmallow, having been told that if they could hold off eating it until the researcher returns, they would get two marshmallows.

Alzheimer's disease currently affects one in 10 people over age 65 and nearly half of those over age 85.

More than 19 million Americans say they have a family member with the disease, and 37 million say they know somebody affected with Alzheimer's.

In the United States, the average lifetime cost per Alzheimer patient is US$174,000. (These figures are from the U.S. Alzheimer's Association).

In a recent news report, I talked about a study of older adults that found that their sense of control over their lives fluctuates significantly over the course of a day, and that this impacts on their cognitive abilities, including reasoning and memory.

You may have heard of “g”. It’s the closest we’ve come to that elusive attribute known as “intelligence”, but it is in fact a psychometric construct, that is, we surmise its presence from the way in which scores on various cognitive tests positively correlate.

In other words, we don’t really know what it is (hence the fact it is called “g”, rather than something more intelligible), and in fact, it is wrong to think of it as a thing. What it is, is a manifestation of some property or properties of the brain — and we don’t know what these are.